persistent auth in SQLite, API chat/logs, agent completion via channel

- Auth: move from state.json to SQLite authed_chats table, with memory cache
- Remove Persistent/state.json, all state now in noc.db
- HTTP API: POST /api/chat (end-to-end LLM), GET /api/logs (failed API requests)
- API logging: store raw request/response for 400 errors in api_log table
- Agent completion: spawn_agent sends LifeEvent::AgentDone via channel,
  life loop picks up with full conversation context and responds
- Config structs: derive Clone for HTTP server
- System prompt: instruct LLM not to add timestamps
- Makefile: rsync without --delete to preserve VPS-only tools

.gitignore

@@ -7,3 +7,4 @@ state.*.json
 target/
 data/
 noc.service
+tools/manage_todo